sacculi

from The Collaborative International Dictionary of English v.0.48

Sacculus \Sac"cu*lus\, n.; pl. {Sacculi}. [L., little sack.]
   (Anat.)
   A little sac; esp., a part of the membranous labyrinth of the
   ear. See the Note under {Ear}.
   [1913 Webster]